The present invention relates to a laundry drum for a drum-type washing machine, dryer or the like.
The use of rotating drum-type washing machine is generally known. It is conventional in such machines to utilize a number, for example three or four agitating paddles projected inwardly in the inside of the drum to promote the tumbling of articles being laundered during the washing and rinsing operation. Great Britain Pat. No. 1,161,219 A issued to Philips Electronic on Aug. 13, 1969 exemplifies a plastic rib of substantially triangular cross-section with closed ends so as to be in the form of a trough fastened to the inside of the drum by means of projections extended from the edge of the trough and being held in two rows of co-operating keyhole slots in the wall of the drum. The keyhole slots are in a mirrored arrangement with respect to a central line between the two rows of the slots. The problem with this arrangement of slots is that it will weaken excessively the wall of the drum, because operational stress within the wall of the drum cannot be distributed into regions between mirrored pairs of slots, thus causing inequalities in stress distribution. On that way stresses are unevenly distributed and failure by breakage may occur when working at a high spinning speed (e.g. 1500 rpm) during washing, rinsing or the like operation.
Moreover, the rib being secured to the cylindrical wall of the drum by the projections provided on the edges of the trough engaging with the co-operating keyhole slots in the wall, obviously another fastening element such as a screw as described in the prior art must be necessary for retaining the rib in position after being engaged with the wall on the ground that the projections will gradually deform plastically subjected to forces exerted from the engagement between the projections and slots and as a result may slide out of the slots over a long period of time.